| Message ID | 20220806000635.472853-1-jmeng@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] tcp: Make SYN ACK RTO tunable by BPF programs with TFO | expand |
On Fri, 5 Aug 2022 17:06:35 -0700 Jie Meng wrote: > Instead of the hardcoded TCP_TIMEOUT_INIT, this diff calls tcp_timeout_init > to initiate req->timeout like the non TFO SYN ACK case. > > Tested using the following packetdrill script, on a host with a BPF > program that sets the initial connect timeout to 10ms. Please make sure to CC the relevant maintainers (./scripts/get_maintainer.pl). Apart from that: # Form letter - net-next is closed We have already sent the networking pull request for 6.0 and therefore net-next is closed for new drivers, features, code refactoring and optimizations. We are currently accepting bug fixes only. Please repost when net-next reopens after 6.0-rc1 is cut. RFC patches sent for review only are obviously welcome at any time.
On Fri, Aug 05, 2022 at 05:06:35PM -0700, Jie Meng wrote: > Instead of the hardcoded TCP_TIMEOUT_INIT, this diff calls tcp_timeout_init > to initiate req->timeout like the non TFO SYN ACK case. > > Tested using the following packetdrill script, on a host with a BPF > program that sets the initial connect timeout to 10ms. Please also cc the bpf mailing list.
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 825b216d11f5..45cc7f1ca296 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -272,8 +272,9 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk, * The request socket is not added to the ehash * because it's been added to the accept queue directly. */ + req->timeout = tcp_timeout_init(child); inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS, - TCP_TIMEOUT_INIT, TCP_RTO_MAX); + req->timeout, TCP_RTO_MAX); refcount_set(&req->rsk_refcnt, 2); diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index b4dfb82d6ecb..cb79127f45c3 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -428,7 +428,7 @@ static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req) if (!tp->retrans_stamp) tp->retrans_stamp = tcp_time_stamp(tp); inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, - TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); + req->timeout << req->num_timeout, TCP_RTO_MAX); }
Instead of the hardcoded TCP_TIMEOUT_INIT, this diff calls tcp_timeout_init to initiate req->timeout like the non TFO SYN ACK case. Tested using the following packetdrill script, on a host with a BPF program that sets the initial connect timeout to 10ms. `../../common/defaults.sh` // Initialize connection 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,FO TFO_COOKIE> +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK> +.01 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK> +.02 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK> +.04 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK> +.01 < . 1:1(0) ack 1 win 32792 +0 accept(3, ..., ...) = 4 Signed-off-by: Jie Meng <jmeng@fb.com> --- net/ipv4/tcp_fastopen.c | 3 ++- net/ipv4/tcp_timer.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)